[aaron695]

> How to extract uranium from seawater for nuclear power

“Concentrations are tiny, on the order of a single grain of salt dissolved in a liter of water”

This sounds way to much, I can boil a litre of water in the kitchen and have a grain of Uranium?

From Yahoo answers

Grain of Salt - 2.25 mg (.00008 ounces).

Uranium - 3 micrograms per liter (0.00000045 ounces per gallon)

Yahoo answers didn't have how much energy 3 micrograms of Uranium can create.

I'd guess if we could get a way to extract it with an algae or something, the energy(sunlight) it uses would be better off stored and burned.

[wtallis]

Going based on numbers from Wikipedia, U-235 is good for 83.14 TJ/kg, but that isotope only has a natural abundance of 0.72%. So 3 micrograms of uranium in the natural proportions would get you around 1800 J ignoring any contribution from other isotopes (ie. you're not using a breeder reactor). That means your uranium extraction method needs to be very energy efficient indeed.

[acidburnNSA]

Oh yeah, you pretty much have to use breeder reactors to use seawater uranium. That has been the plan all along, e.g. Cohen 83: http://large.stanford.edu/publications/coal/references/docs/...